MgZnO/SiO₂/ZnO metal–semiconductor–metal dual-band UVA and UVB photodetector with different MgZnO thicknesses by RF magnetron sputter

Abstract

The MgZnO/SiO2/ZnO metal–semiconductor–metal (MSM) dual-band UVA and UVB photodetectors (PDs) with different MgZnO thicknesses were fabricated by RF sputter. From the dark current, it was found that the PD with 200 nm thick MgZnO had a lower leakage current, which implies less defect density and better crystal quality. Therefore, the FWHM of the X-ray diffraction and grain size of the scanning electron microscope image for PDs with a thicker MgZnO thickness were narrower and larger than those of the others. From the photoluminescence (PL) at room temperature, the main defect types of the MgZnO/SiO2/ZnO thin film included Ov, Oi, and Zni. Then, a variable and voltage-controlled tunable wavelength of UV PD from UVB to UVA can be well accomplished by using a SiO2 blocking layer inserted between the MgZnO and ZnO thin film. Therefore, at a lower and higher bias voltage, the PD with a 200 nm thick MgZnO can detect the UVB and UVA range, respectively.

The enhanced responsivity and response speed of SnO2 visible-blind transparent photodetectors via the SiO2 passivation layer

“…16,17 The SiO 2 layer can be used to improve the on/ off ratio of ZnO film PDs. 18,19 And the response speed of TiO 2 based UV PDs can also be enhanced by coating an SiO 2 layer. 20 Among these dielectric materials, SiO 2 has become one of the most suitable candidates due to its easy manufacture, low cost, high chemical stability and abundant natural properties, which also match well with the characteristics of the SnO 2 material.…”

Ultrahigh Responsivity In2O3 UVA Photodetector through Modulation of Trimethylindium Flow Rate

“…Ultraviolet-A (UVA) photodetectors (PDs) have attracted wide attention in both civilian and military applications, such as flame detection, ultraviolet cameras, and missile early warning systems [1][2][3][4][5][6][7][8][9]. Indium compounds such as In 2 Se 3 , In 2 S 3 and In 2 O 3 are widely reported for efficient photoelectric detection [10][11][12][13][14][15][16][17][18].…”